A total of 464 sedentary, postmenopausal women at moderate risk for cardiovascular disease was randomly assigned to receive exercise training at one of three doses (4, 8, or 12 kcal/kg/wk) or no exercise for six months duration. The specific aims were be to determine: (a) if women in the exercise groups have increased aerobic power (VO2max) over the six months compared to the no exercise group; (b) if women in the exercise groups have a greater reduction in resting systolic blood pressure than those in the no exercise group; and, (c) if there will be a dose-response gradient across the three exercise groups for changes in aerobic power and systolic blood pressure. Secondary aims include evaluating the effects of exercise dose on fasting blood lipids and lipoproteins, glucose, insulin, anthropometry, self-reported quality of life, and cardiovascular risk as determined by a multiple logistic risk function. Covariates to be controlled included dietary intake, physical activity (outside of the exercise program), smoking, alcohol intake, sleep habits, medication use (including hormone replacement therapy), demographics, menstrual history, personal and family medical history.